KaiGPT

KaiGPT Claude Messages API

Claude Messages relay route. The docs give https://gptzzz.ai/v1/messages for Claude Messages requests and say Claude clients must use that protocol configuration rather than the OpenAI request body; the gateway accepts the key in the x-api-key header.

GitHub

Documentation

📖
Documentation
https://gptzzz.ai/docs/
📖
Documentation
https://gptzzz.ai/blog/claude-api-quickstart/
📖
Documentation
https://gptzzz.ai/blog/claude-code-api-relay/

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This API 
curl "https://apis.io/api/v1/apis/gptzzz:kaigpt-claude-messages-api"
All apis 
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

API entry from apis.yml

apis.yml Raw ↑ 
aid: gptzzz:kaigpt-claude-messages-api
name: KaiGPT Claude Messages API
description: Claude Messages relay route. The docs give https://gptzzz.ai/v1/messages for Claude Messages
  requests and say Claude clients must use that protocol configuration rather than the OpenAI request
  body; the gateway accepts the key in the x-api-key header.
humanURL: https://gptzzz.ai/blog/claude-api-quickstart/
tags:
- Claude
- Message
- LLM Gateway
tags_raw:
- Claude
- Messages
- LLM Gateway
properties:
- type: Documentation
  url: https://gptzzz.ai/docs/
- type: Documentation
  url: https://gptzzz.ai/blog/claude-api-quickstart/
- type: Documentation
  url: https://gptzzz.ai/blog/claude-code-api-relay/